Gear arrangement for transmissions



Nov. 4, 1952 R. G. LE TOURNEAU 2,616,301

GEAR ARRANGEMENT FOR TRANSMISSIONS Filed Jan. 18, 1950 2 SHEETSSXIET 1 IN VENTOR R G. LETOURNEAU AGENT Nov. 4, 1952 'R. G.}LE TOURNEAU 2,516,301

GEAR ARRANGEMENT FOR TRANSMISSIONS Filed Jan. 18, 1950 2 SHEETSSHET 2 /NVENTOR R G. LETOURNEAU AGENT Patented Nov. 4, 1952 UNITED STATES PATENT OFFICE GEAR ARRANGEMENT FOR. TRANSMISSIONS Robert G. Le Tourneau, Longview, Tex.

Application J anuary 18, 1950, Serial No. 139,263

Claims. 1

This invention relates generally to transmissions and more particularly to transmissions with multiple stage forward and reverse speeds.

The primary object of this invention is to provide a transmission having multiple stage forward speed ratios and having multiple stage reverse speeds of a difierent ratio.

Another object of this invention is to provide a constant mesh transmission in which each of the stages include a sleeve gear operated gear train and a shaft gear operated train and in which the reverse speeds are obtained thru a difierent shaft gear operated gear train than the forward speeds.

A further object of this invention is to provide a gear arrangement in which the shaft gears are grouped in a compact circle about the output shaft so that both the shaft gears and sleeve gears will occupy the smallest possible space and may consequentlybe enclosed by a case of minimum volume when used as a removable bolt-on type transmission.

Other objects and advantages will become apparent from a perusal of the following specification and the .accompanyingdrawings, in which:

Fig. 1 is a 'diagrammatic perspective view illustrating the gear trains of both the sleeve and shaft gears.

Fig. 2 is an end view of the clutch end of a bolt-on transmission employing this gear sequence showing the compact grouping of the ears.

Fig. 3 is an end view of the mounting end of the transmission of Fig. 2.

Referring now to the drawings, in Fig. 1 the reference numeral i indicates generally the sleeve gear train and numeral 2 the shaft gear train. These two 'groupings are so named since the individual gears 3l revolve with hollow sleeves 8 l2 and gears l3ll revolve with solid shafts iB-22. The force and motion is transmitted between the shaft and sleeve thru the medium of the air operated clutch units 2321 in the manner described in detail in co-pending application Serial No. 735,484, filed March 18, 1947, now U. S. Patent No. 2,553,376. The output shaft 28 contains a small gear 29 and a large gear 30 which both revolve with the shaft When either receives torque from either of the gears l3l5. Helical bevel gear 3! is on the same shaft 28 and consequently turns with either output gear and subsequently delivers power to a final drive mechanism. Shaft 21 is spline connected thru adapter coupling 32 to a taire-Off shaft 33 from the power plant and this shaft acts as the power input to the transmission.

When the engine clutch 26 is engaged, the sleeve gear 6 turns at the same rotary speed as shaft 33, but the speed transmitted to shaft 9 is reduced greatly due to the gear ratio between the large gear 4 and gear 6. This same speed is delivered to shaft 19 when clutch 24 is engaged. However, shaft l9 contains a gear Hi which meshes with a small output gear 29 so that the speed of shaft 28 is again stepped up. This constitutes one speed of the reverse gear output. The other reverse speed is obtained by engaging clutches 21 and 24 so that the sleeve gear train becomes 154 and the shaft gear is again l4, but at this moment it is running at a speed of approximately one-half its former.

In the former application (735,484), there were two reverse shafts and consequently four reverse speeds. These reverse speeds corresponded to the four forward speeds of the Vehicle. In the present invention, there are four forward speeds, but the tWo reverse speeds now correspond approximately to the 2nd and 3rd speeds of the forward. This is desirable since in tracter work four reverse speeds are not essential, but a faster reverse speed than the 2nd forward speed is usful. In order to eliminate one shaft and one set of sleeve and shaft gears (high reverse) from the former transmission and at the same time evolve an intermediate set of reverse speeds, it is necessary to engage the shaft gear of the remaining reverse shaft with the smaller output gear. Since the IOW- forward gear I5 meshes with a large output gear 30 and the reverse gear l4 meshes with a small output gear 29, the reverse output will be at a higher speed in each instance than the low forward output; i. e. when powered from either engine gear 6 or compound gear l. 7

The remaining gear sequences in this trans mission are substantially as in the former application: engine gear l6 is in mesh with compound gear l1 which has approximately twice as many teeth; both these shaft gears are connected thru clutches 26 and 27 to their corresponding sleeve gears 6 and 1. These latter gears selectively furnish power to the sleeve gear train 1. When either clutch such as 21 is engaged, all of the gears 3-! in the sleeve gear train revolve, and if clutch 26 is engaged they would revolve at approximately twice the speed. When a speedselection clutch such as 23 is engaged, shaft l8 would then turn at the same rate as shaft 8 and gear 3. This speed would be increased in trans mission by gears l3 and 29 to output shaft 28, and the ultimate final speed taken off thru gear 3l would correspond to the third forward speed.

During this sequence, gears 14 and 15 and shafts l9 and 20 would be idiing in accordance with the speed under power being delivered to output shaft 28.

In Figs. 2 and 3, it will be seen that case 34 is generaliy circular in shape which will facilitate machining but has protrusions 35 to accommodate those gears which will not fit in the circu- 1ar enclosureandthafi' the overailivolume thus* obtained" includes a minimum of' wasted space. The elimination of one reverse shaft and yet retaining the same practical utility to the trans mission contributed to themrallreducedvolume. To obtain a generally circu1ar case and yet one with a minimum volume; th-case 3'4=is made to enclose as many gears;ofi thetwo.,gear trains as possible, then the gears which cannot be brought into this circle will be accommodated by we1ded or cast protrusibns which inclose them; a. gear:whioh is in. mEh. with: these protruding gears. (suchas:1owforwardzgearsa)' is. waiked around.the gear teeth: (of :gear l since* itszcorre; sponding .-gear:.l1- is pmtruding% until. it. is in mesh:withanother gearof its: train.- Actually the:overali design: takes.in:manyfactors such .as desired tooth ratio, strength, (etc; whichgowita this feature to produce:amencflosed transmission ofgenerally -circuiar shape but minimum volume;

:From the :foregoingflescription, it will:ba readily; seen thatthere: has beenproduced:such a dev-ice assubstantiaily :fulfills: the: objects of' the invention as" set forth herein.

While thisv specification sets -forth in -detail the present and preferred construction of the device,;still in practice such deviation -from such 2 data-i1 may be*resorted:to T&St=d0 *not forma departure-from the spirit of: theinvention as -definedby the: appended .claims;

H vin thus described.my; invention, the: foliowing;is .claimed:as .newand usefu1; and upon whichLetters Patent is desired:

L A:-transmission.comprisin: a::case; ai'par ofigear: trains.:mountedwithin:saidcase aseries OTH&III&L shaftsmounted:in saidi case :and pr imting;thcrefrom; OHOLSfiEd gear.trains:having its;- Lgears: mounted on ..said shats; :arseries of paraliel sleev mounted-in said caseandfiprojecting therefrom ami-the:- other of' said: gear trains.havingy its ;g.ears mounted: on said..sleeves; each :of said sieeves bteing :a1igned ;upon and: surrounding one=endofi a corresponding;one of said shafts: a seriesz of;;clutches --associated -with said sieeves: and shafts;;each .separateone .of..said clutches bein g :associatedwith a:corresponding separate one :of :saidaligned:shafis andsslecves for binding its associated: shaft :and -sleeVe for: joint rotation; a shaft gear adapted to be driven;by an-engine: a larger compound.gea. driven*by said engine gear; said:sieeve :mountedgear train including:corresponding ;non-meshing-engine and compound :gea-rsand a?forwardgeartand.a:reverse gear meshing with each* :other; said. forward s1eeve mounted gearrmeshing with said com- .poundsieeve..mountedgear; said reverse sleeve mounted:gear:meshingwith said sleev.e.mounted engine gear; an-. output shaft; aiarge gear and a.sman gear mounted:onsaid output shaft; said .shaftmounted gear train includinga forward gear adaptedto rotatewith:said-sleeVe-mounted forward gear whenthe= connectingclutch is :en

gaged; said shaft.mounted forward gear meshing with said large gear; said shaft mounted ear train including a reverse gear adapted to .rotate with.said sieeyemounted reversegearwhen their coinecting c1utch is --engaged; said reverse -and r each .ofsaidsleeveabeing aligned upon and surrounding one endof a corresponding one of said shafts; a: seriesoi clutches associated with the -cxternal.endsof said.sleeves and shafts, each separate one ofsaid" clutches being associated. with a..zcorresponding separate one of said aligned shafts and sleeves for biiiding its associated shait andsleeve for joint,rotationselectivcl.; -a .shaft gear: adapted to be .driven by :an. external.power source; a larger compound gear.driven bysaid power gear; saidsleeve mounted gear trainincluding corresponding non-meshing power and compoundgearsanda forward gear.andaneverse gear meshing with each.other said forWardlsleeve mountedgear meshing With.;said'compoundsIeeve mounted gear; said reversesleeve mounted. gear meshing: with saidsleeve mounted'powergear;

an output:.shafit; a large gean and a small gear mounted:on:said outputshaft; said'sliaft mounted.gear train including.a.fcrward gear adapted to rotate with said SleVe mourted'0rward gear when the connecting clutch Lis. engagd; said shaft mounted forward gear meshing with said l.rgegear said shaft. mounted'gear train including a. reverse gear:v adapted torotate with said sleave mounted reverse gear when their connecting c1utch.is engaged; said reverse. and forwar.d shaft..mountedgears heing adapted to rotate .at approximately the same speed; said shaftmounted.rever gean meshing with sziidlsmaLllgear.

.3.-Ai:ansmssibn as in daim 1,,saicl casebeing mainly'crcular. in .shai. ,protrusiom. .extending f1:o1n. the..circumferencevofsaid case or inclusion of.certain ofsaid s'haft.and sleeve gears, the gears meshing with said protrudinggears being,.rotated.around.said protrnding gear .shaft untiLas. nearly .as possible inclded within said circular case.

4. A transmission as in claim l,said'case heing general1y circular and. unitary said clutches being mounted on said sleeves and extending b.e. yond theenciosure .of.the.oase.

.5. A transmission.as.fl1 claim..l,,.saidclutches being .mounted on. said sleeves and extending beyond the-.enclosune of-the.case, said case. being filledwith. oil, and said clutches .being oi1 free.

ROBERT. G. LETOURN EAU.

REFERENCES' 'CITED The following .references are of recordrin the file :of this patent:

UNITED STAIES PATENTS Number Name- Date.

1,589,267. Toomey June 15, 1926 1,993,983 Woodward- Man. 12, 1935 'FOjREIGN PATENTS Number Country Date "254,415 Great-Britain July 8, 1926 462 365 Great.Bfltaih' Mar. 8, 1937 523,771 Great Britain- -July.z3, 19.40 

